Answer:
An illegal drug
Step-by-step explanation:
the other options for this question were:
a prescription drug
an over the counter drug
a medicine
A prescription drug is legal to manufacture by a licensed professional and is legal to buy with a doctor's prescription note
an over the counter drug is legal to manufacture by a licensed professional who can sell it and a person can buy it with a doctor's approval.
regular medicine is not illegal to manufacture or sell and anyone can buy it and use it according to the label.
If a drug is illegal, then nobody is allowed to manufacture it and they would be convicted of a felony if caught doing so. Since the drug is illegal, you're not allowed to buy or sell it.